currently, there is not really a difference between Neuron2Robot and Robot2Neuron TFs. However, the system keeps the two of them seperate and currently executes first all Robot2Neuron TFs and then all Neuron2Robot TFs. In the future, we reserve the idea to run the two groups of TFs in parallel as we assume that they won't interact with each other. This was also the original idea why we introduced two different types.

As a bonus, Neuron2Robot allows you to specify a default topic to which the return value of the TF should be sent.

However, we received plenty of requests to make that error you experienced to go away. Therefore, we started to make these decorators optional. This usability improvement is already merged in the development branch and will be in the Bitbucket soon.